1. Field of the Invention
The invention relates to a wound closure device, and more particularly, the invention relates to a device and method for facilitating hemostasis of a biopsy tract or other puncture wound by injection of an absorbable sponge.
2. Brief Description of the Related Art
Percutaneous needle biopsy of solid organs is one of the most common interventional medical procedures. Millions of percutaneous needle biopsies are performed annually in the United States and throughout the world. Percutaneous biopsy is a safe procedure which has supplanted surgical biopsy for many indications, such as skin biopsy and liver biopsy.
Possible complications of needle biopsy include bleeding at the biopsy site. The amount of bleeding is related to a number of factors including needle size, tissue sample size, patient""s coagulation status, and the location of the biopsy site. Vascular organs such as the liver, a common biopsy target, may bleed significantly after needle biopsy. To minimize bleeding from a biopsy site, small-gauge needles are typically used. Small gauge needles, however, produce less satisfactory biopsy specimens but frequently are favored over larger bored needles because of their perceived safety. In order to minimize the chance of internal bleeding after biopsy, external pressure is applied and patients are often asked to lie in uncomfortable positions, such as the lateral decubitus position, for a number of hours, particularly after liver biopsy.
Sterile sponges, such as Gelfoam, are prepared in dry sterile sheets which are used as packing material during surgery for control of bleeding. The sponge sheets are left in the surgical site after surgery to stop bleeding and are absorbed by the body in 1 to 6 weeks. A number of techniques have used these absorbable sterile sponge materials to plug a biopsy tract to minimize or prevent bleeding. The absorbable sponge provides a mechanical blockage of the tract, encourages clotting, and minimizes bleeding though the biopsy tract. Despite the advantages of using absorbable sponge to plug a biopsy tract this technique has not achieved widespread use because of difficulty in preparing and delivering the sponge material into the biopsy tract.
One example of a biopsy wound closure device using an implantable sponge is described in U.S. Pat. No. 5,388,588. According to this patent, a circular sponge of an absorbable foam material is precut and inserted into a biopsy site by an applicator rod having the sponge positioned on the end. Once the sponge is implanted, the sponge absorbs blood and swells to fill the tract preventing further bleeding at the biopsy site. However, the sponge is difficult to deliver and expands slowly once delivered. In addition, this delivery method can only deliver a sponge of a limited size which provides less local compression than desired and may incompletely fill the target site. Further, bleeding may continue along sections of the biopsy tract where no sponge has been delivered.
Accordingly, it would be desirable to provide a device and method which will permit the delivery of an absorbable sponge to a biopsy tract in a simple and reliable manner.
The present invention relates to a device and method for facilitating hemostasis of a biopsy tract or other puncture wound by injecting an absorbable sponge. The system according to the present invention allows the sponge to be delivered in a hydrated state through the biopsy needle or other cannula directly into the puncture wound.
In accordance with one aspect of the present invention, a system for injecting a sponge into tissue includes a pledget of sponge having a proximal end with a larger cross sectional area than a distal end, a cannula for delivering the pledget in a hydrated state to the tissue, and an adaptor connectable to the cannula for hydrating and delivering the pledget to the cannula, the adapter having a tapered lumen with a large diameter proximal end and a small diameter distal end, wherein the small diameter distal end is connectable to the cannula.
In accordance with an additional aspect of the present invention, a method of forming a sponge pledget for delivery to tissue includes steps of cutting a strip of sponge from a sheet of sponge material and folding the strip to form a pledget with a first end having a first cross sectional area and a second folded end having a second cross sectional area which is larger than the first cross sectional area.
In accordance with a further aspect of the present invention, a system for preparing and delivering a hydrated sponge to a cannula for delivery to tissue includes an adaptor and a template. The adaptor includes an elongated member having a first end, a second end, and a lumen extending from the first end to the second end, a luer connector provided at the second end for connection to a cannula, a tapered section of the lumen tapering from a first diameter at the first end to a second diameter at the second end which is smaller than the first diameter such that a dry sponge pledget having a width larger than the second diameter is compressible when hydrated to allow passage of the pledget into the second diameter. The template is configured for use in cutting the sponge to a size to be received in the elongated member for delivery to the cannula.
In accordance with an additional aspect of the invention, an adaptor system for delivering a hydrated sponge to a cannula for delivery to tissue includes an elongated adaptor having a distal end, a proximal end, a lumen tapering from a larger diameter at a proximal end to a smaller diameter at the distal end, and a luer connection at the distal end, and a removable vent cap configured to engage the luer connection, the vent cap having a vent hole which allows fluid to pass out of the adaptor through the cap but prevents the sponge from passing through the vent hole.
In accordance with another aspect of the invention, a method of delivering a sponge into a tissue access tract includes the steps of delivering a hydrated sponge pledget through a cannula positioned in a tissue access tract at a velocity E while withdrawing the cannula from the tissue at a velocity V to deposit the sponge pledget and seal the tissue access tract, wherein the velocity E is greater than or equal to the velocity V.